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This function makes the adapter start scanning for other devices.
It will find all the paired devices as well as the devices that match the provided parameters.
It is also used to receive BLE advertisement data.
Input:
transport : SINT (0..2) (default 0)
The type of device to search for:
0 Any kind
1 Classic Bluetooth.
2 BLE.
UUID : STRING
Scan for a specific profile that has this UUID. Note that some devices may not have all profiles available to unpaired and unconnected devices.
The official UUIDs can be found in the Bluetooth specification (https://www.bluetooth.com/specifications/assigned-numbers/service-discovery).
RSSI : INT (default 0)
The required signal strength in dB.
pathloss: INT (default 0)
The device must advertise TX Power and have a computed pathloss less than this value.
timeout : DINT (default 0)
The timeout in seconds before stopping the scan automatically. If set to 0, it will keep scanning until btScanStop is called.
Returns: INT
1
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-
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_BT_OK
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Success
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0
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-
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_BT_ERR_NOT_SUPPORTED
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The API is not supported.
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-1
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-
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_BT_ERR_NOT_OPEN
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The adapter is not powered(see btPower).
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-5
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-
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_BT_ERR_NO_ADAP
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Could not find adapter.
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-12
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-
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_BT_ERR_BUSY
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Adapter is already scanning.
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-17
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-
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_BT_ERR_TIMEOUT
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Failed to start scan withing the expected time.
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Declaration:
FUNCTION btScanStart : INT;
VAR_INPUT
transport : SINT := 0;
UUID : STRING := "";
RSSI : INT := 0;
pathloss : INT := 0;
timeout : DINT := 0;
END_VAR;
Example:
INCLUDE rtcu.inc
PROGRAM test;
VAR
rc : INT;
idx : INT;
address : STRING;
devInfo : btDeviceInfo;
i : INT;
END_VAR;
rc := btPower();
DebugFmt(message:="btPower: \1 ", v1:=rc);
BEGIN
IF btIsScanning() <> 1 THEN
rc := _BT_OK;
idx:=1;
WHILE rc >= _BT_OK DO
rc := btDeviceGet(idx:=idx, dev := address);
IF rc >= _BT_OK THEN
DebugFmt(message:="Address(\2): \1 , " + address, v1:=rc, v2:=idx);
devInfo(dev := address);
DebugFmt(message:=" " + devInfo.name+" , Class: \4, type: \3, connected: \1, tx power: \2",
v2:=devInfo.tx_power, v4:=devInfo.clss, v3:=devInfo.addr_type, v1:=SINT(devInfo.connected));
DebugFmt(message:=" status: \1, paired: \2, trusted: \3", v1:=devInfo.status,
v2:=INT(devInfo.paired), v3:=INT(devInfo.trusted));
DebugFmt(message:=" Profiles: \1", v1:=devInfo.profiles);
FOR i:= 1 TO 16 DO
IF devInfo.uuid[i] <> "" THEN
DebugFmt(message:=" [\1]: " + devInfo.uuid[i], v1:=i);
END_IF;
END_FOR;
END_IF;
idx := idx+1;
END_WHILE;
DebugFmt(message:="btDeviceGet: \1 ", v1:=rc);
rc := btScanStart(timeout := 5, transport := 1);
DebugFmt(message:="btScanStart: \1 ", v1:=rc);
ELSE
Sleep(delay:=100);
END_IF;
END;
END_PROGRAM;
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